Synergistic insecticidal compositions comprising an 0, 0-di-alkyl thiophosphate-4-methylumbelliferone



United States Patent M SYNERGISTIC INSECTICIDAL COMPOSITIONS COMPRISING AN 0,0-DI-ALKYL THIOPHOS- PHATE-MVIETHYLUMBELLIFERONE Gaines W. Eddy, Corvallis, 0reg., and Edward F. Knipling, Arlington, 'Va.; dedicated to the free use of the Peoplein the territory of the United States No Drawing. Application June 14,1954 Serial'No. 436,743

t 9 Claims. '(Cl.167-33) (Granted under Title3'5, U. S. Code (1952), sec. 266) A non-exclusive, irrevocable royalty-free license in the invention herein described,for alllgovernmentalpurposes,

throughout the world, with the power to grant sub-licenses for such purposes, is hereby granted tothe Government of the UnitedStates of America.

We hereby dedicate the invention herein 'described to the free use of the People in the territory of the United States.

This invention relates to insecticides, in particularlto the so-called organic phosphate insecticides, such'as parathion.

These organic phosphates arekuo'wn to be 'toxiclto -warm-blooded'animals in that theywill lower the cholinesterase content of the blood by *absorption'through'the skin, byinhalation orby oral ingestion.

i The present invention accomplishes an increasing :dffthe toxic action to insects "by including certain non-toxic materials which are themselves not insecticides but which act as synergists when mixedwith the organicphosphates inan amount rangingabout from .025 to .05 otthe *synergist tol/ 10' thereof, that is,. L0025% to .005'%,respectively,"of the organic phosphate. .These synergi'sts are "1,2 methylenedioxy-4-[2-(octylsulfinyl)propyl] t benzene (known assulfoxideyand the alphaisopropylpiperonyl ester of chrysanthemum monocarboxylic acid. "In 'this manner it is possible to use the organic phosphates at a sufiiciently low concentration as to be relatively non-toxic'to warm-blooded animals and yet'obtaina"mixtute of high insecticidal potency.

The invention is applicabletwa'nurnber'of'organic phosphates which may be generally described by the formula:

wherein R and R are identical alkyl radicals selected from the group consisting of methyl and ethylyand R is a member of the group consisting of hydrogen and chlorine. Examples =of'such, phosphates and theirtstructurlal formulae are:

0,0:-diethy1 O 4-methylumbelliferone thiophosphate 2,826,530 Patented Mar. .11, 1,958

O-(3-chloro 4 methylumbelliferone) 0,0 diethyl thiophosphate and "G-(*3 chloro-4-methylumbelliferone) 0,0 dimethyl thiophosphate These compounds were tested in admixture with a variety of synergists and when compared with other phosphates, also'tested in admixture with a variety of synergists,it was'foun'd that the combination of each of the said compounds with each of 1,3-methylenedioxy-4-[Z-(octyl- .su1finyl)propyl]benzcne.or alphaisopropylpiperonyl ester or chrysanthemum monocarboxylic acid as a synergistic agent gave highlysuperioh results. The'data on these tests "are given in Tables'l to -V,'inclusive,.hereinafter. Some of the otherphosphates tested and their structural .for- 'mulae are given hereafter:

'Tetrapropyl dithiopyrophosphate Testsireported "herein were made with thethuman body louse, Pediculus-humanus humanus (Degt), asthe test insect, the chemical mixtures. being usedasI cloth impregnantsnand as powders.

in "the. impregnation tests thecmixtures were dissolved inacetone'at the desired concentration-and 0.7 ml. of the test solution was added by pipette to circular cloth patches 1.5 inches indiameter. The treated patcheswere sustpended on pins and allowed to,idry..-for'aboutianhour, after -which each pad was placed in a SO mlgbeaker and "20 adultlice'(10 of each sex) introduced. For testing, the beakers were held in an incubator at 30 C. and morasaaaso tality records were made after 24 hours. For aging, the treatments were held indoors at room temperature.

In the powder tests, the mixtures were applied to small balbriggan cloth patches and the insects were confined on the treated cloth. Examinations were made at various time intervals to determine their toxicity to the insects. The powders were handled and aged in the same manner as the cloth impregnants.

Tests against body lice were conducted to determine the immediate and residual effectiveness of certain of the organic phosphates when mixed with 1,2-methylenedioxy- 4-[2-(octylsulfinyl)propyllbenzene as the synergist. Preliminary tests were run with the organic phosphates at several low concentrations in order to select dosages that would show synergistic action of the 1,2-methylenedioxy- 4- 2- octylsulfinyl propyl benzene.

Each organic phosphate was tested at a range of three concentrations, alone and combined with the synergist. A ratio of 1 part of the organic phosphate toxicant to 10 parts of the synergist was used in these tests, although synergism was evident with other ratios. In a second series of tests the phosphates were tested for residual eflect at a concentration of 0.005 percent alone and combined with 0.05 percent of the synergist. in these tests l-hour knock-down records were taken in the initial exposures and 24-hour exposure tests were conducted twice weekly for 3 weeks.

gist 1:10; 20 adult lzce of each sex) exposed for 24 hours.)

Percent knock- Percent .condown .1 an

centration mortality after 10 Toxicant 24 hours Toxi- Syner- Knock- Mortalcant gist down ity 0. 005 0.05 100 90 .0025 .025 100 85 0,0-Methyl O-4-methy1umbellifer- .001 .01 5 0 one thiophosphate .005 0 a .0025 0 0 .001 0 0 .005 .05 100 70 .0025 .025 100 60 20 O-(3-chloro-4-methylurnbclliferone) .001 .01 15 15 0,0-diethyl thiophosphate .005 10 10 .0025 15 5 .001 0 0 Cheek-untrcated 0 0 In the first series of tests, the results of which are shown 7 in Table l, the synergist caused remarkable increases in the effectiveness of both phosphates. An 0.005 percent concentration of the toxicant alone caused only 20 and 10 percent knock-down and 0 and 10 percent kill in 24 hours, while with the synergist the knock-down and kill were 100 and 90, and 100 and 70 percent, respectively. Half this concentration of the toxicant was completely inetfective in both cases, but when combined with the synergist, the knock-down and kill were 100 and 85, and 100 and 60 percent. oxy-4- [2- octylsulfinyl propyl] benzene (sulfoxide) alone at 0.05 percent was completely inefiective. The other synergist, namely, the alpha-isopropylpiperonyl ester of chrysanthemum monocarboxylic acid, alone at .05% was similarly substantially complete inefiective.

The synergist namely, 1,2-methylenedi- Table 1.Results of beaker tests with umbelliferone phosphate compounds at low concentrations alone and combined with a synergist, 1,2-methylenedioxy-4-[2-(0ctylsulfinyl)propyl]-benzene. (Ratio of toxicant to syner- Knock-down also includes those listed as dead.

Seventeen other materials acted as synergists for the 0,0-diethyl O-4-methylumbelliferone thiophosphate, O- (3chloro-4-methylurnbelliferone) 0,0 diethyl thiophosphate, and O-(3-chloro-4-methylumbelliferone) 0,0-dimethyl thiophosphate. 1,2-methylenedioxy-4- [2-(octylsulfinyl)propyl]benzene was included as a standard of comparison. The toxicants were tested at concentrations of 0.005, 0.0025, and 0.001 percent, alone and in combination with each synergist at a ratio of 1:10. The results of the tests are presented in Table 2. As can be seen, all the synergists increased the toxicity of the phosphates.

Further tests were conducted with a concentration of 0.005 percent of the phosphate and 0.05 percent of each synergist to determine the residual effectiveness of the materials. Results of these tests are presented in Table 3. All 17 synergists increased or prolonged the residual action of umbelliferone esters of thiophosphoric acid to a remarkable degree.

bination with various synergists.

to toxicant 10:1; 20 adult lice (10 of each sex) exposed for 24 hours.)

(Ratio of synergist Synergist Percent knock-down and kill (combined) at indicated concentrations 0,0-diethyl O4-methyl- O-(3-chloro-4-rnethyl- O-(3-chloro-4-methy1- umbelliterone ester umbelliferone) 0,0- umbelliterone) 0,0- IltIem Name diethyl ester dimethyl ester N-Isobutylhendecenamide 100 100 0 Plperonyl butoxide 100 100 0 100 100 0 100 95 10 1,2methylened1oxy-4-[2-(octylsulflnyl)-propyl] benzene 100 100 25 100 100 0 100 100 0 Chrysanthemummonocarboxylic acid, alpha-allylpiperonyl ester .s 100 100 35 100 100 0 N-Z-ethylhexy 0[ 100 100 30 100 100 n-Propyl isome 100 95 100 35 0 1,2-methylened1oxy-4-[2-(oetylsu1t0nyl)-propyl] benzene 100 0 Propionic acid, p-(alpha, alpha-dimethyl-benzyl) phenyl ester. 90 90 Propionic acid, p-cyclohexylphenyl ester 100 70 Propionic acid, 2,4-di-tert-butyl-6-isopropylphenyl ester" 100 30 alpha-Propylpiperonyl acetate 100 100 Ghrysanthemurumonocarboxylic acid, alpha-propylpiperonyl ester 100 100 100 100 5 100 0 Ohrysanthemummonocarboxylic acid, 4-(3,4-methylenedioxy- I phenyD-sec-butyl ester 100 100 90 Chrysanthemummonocarboxylic acid, alpha-ethylpiperonyl ester 100 100 90 100 100 20 100 100 10 5-butyl-f S-ethyl-?- (3,4-methylenedioxyphenyl)-m-dioxane 100 100 90 100 100 10 100 100 70 Fencholrc acid, alpha-allylpiperonyl ester-.. 100 100 70 100 100 25 100 100 55 Ohrysanthemummonocarboxylic acid, alphaester 100 100 100 100 95 0 100 100 25 Toxicant alone 15 0 0 15 0 90 10 0 asset-e0 7 We-claim: 1. An insecticide comprising a mixture containing as a toxicant an organic phosphate having the'formula from the group consisting of methyl and ethyl, and R is a member of the group consisting of hydrogen and chlorine and, as a synergist'therefor, a member selected from the group consisting of 1,2-methylenedioxy-4-[2-(octyl-i' sulfinyl)propyl] benzene and the alpha-isopropylpiperonyl ester of chrysanthemum monocarboxylic acid, said toxicant and synerg i st being present in the proportions of about from .0025 to .005 of toxicant to .025% to ".05%, respectively, of the synergist,

2. The insecticide of claim 1 wherein the synergist is 1,2-methylenedioxy-4-[2(octylsulfinyl)propyl] benzene. 3. The insecticide in claim 1 wherein the toxicant is 0,0-diethyl O-4-methylumbelliferone thiophosphate and propyl] benzene.

4. The insecticide of claim 1 wherein the toxicant is O-(3-chloro-4-methylumbelliferone) 0,0-diethyl thio phosphate and the synergist is 1,2-methylenedioxy-4-[2- (octylsulfinyDpr'opyH benzene.

5. The insecticide of claim 1 wherein the toxicant is 0-(3-chloro 4-methylumbelliferone) 0,0-dimethyl thiophosphate and thesynergist is 1,2-methy1enedioxy-4-i2- (octylsulfin'yDpropylJ benzene. V

6. The insecticideof claim 1 wherein the synergist is O,'O-diethyl O-4-methylumbelliferone thiophosphate and the 'synergist is the alpha-isopropylpiperonyl ester of chrysanthemum monocarboxylic acid.

The insecticide of claim 1 wherein the toxicant is wherein R and R areldentrcal alkyl radicals selected O-(3-chlorol-methylumbelliferone) 0,0-diethyl thio- 1 phosphate and the synergist is the ,alpha-isopropylpiperonyl ester of chrysanthemum monocarboxylic acid.

. 9. The insecticide .of claim 1 wherein the toxicant is O-(3-chloro 4-methylumbelliferone) 0,0-dimethy1 thiophosphate and the" synergist is the alpha-isopropylpiperl onyl ester of Chrysanthemum monocarboxylic acidj ReierencesiCited the file of this patent z "UNITED STATES PATENTS OTHER REFERENCES Hoffman et al.: J. Econ. Ent. (February 1954), vol.

i 47, No. 1, pp. 72-76;

King: Chemicals Evaluated'as Insecticides, U. S. Dept.

I Agr. Handbook 69, p. 115, Item No. 20, 337, May 1954. 

1. AN INSECTICIDE COMPRISING A MIXTURE CONTAINING AS A TOXICANT AN ORGANIC PHOSPHATE HAVING THE FORMULA 